Homeostasis and Reward: T-Maze Learning Induced by Manipulating Antidiuretic Hormone

This chapter provides information on an experiment that aims to determine whether other deviations from homeostasis instead of a deficiency, an excess of H₂O, will serve as a drive to motivate learning. It aims to whether the correction of these deviations by an internal glandular, instead of an external consummatory, response can serve as a reward to reinforce learning. The general design of the experiment was to give one group of rats a water load immediately before each learning trial in a Tone (T) maze. Albino rats were injected with antidiuretic hormone (ADH) if they chose one arm of a T maze and with isotonic saline vehicle if they chose the other one. While the ADH interfered with the return to homeostasis by the water-loaded rats, it aided the return to homeostasis by the salt-loaded rats with diabetes insipidus because it allowed them to reabsorb water so that they could excrete urine of higher NaCl concentration.